The ink-jet recording method is a method for recording an image or a character by flying fine droplets by various operation principles to adhere onto recording medium. Recently, the method has been rapidly spread since the method has merits such as that relatively high speed printing and low noise printing can be performed and multicolor printing can be easily realized. Moreover, the method has been applied to a high quality printing such as photographic image. Consequently, recording medium having high ink absorbability and that without foreign substance and clack on the surface and improved in the producing efficiency, and a producing method of such the recording medium are required.
Many proposals have been disclosed for satisfying these requirements.
Many recording medium have been proposed, for example, the recording medium described in Japanese Patent Publication Open to Public Inspection, hereinafter referred to as JP O.P.I. Publication, No. 52-53012 which is constituted by a low-sized raw paper in which a coating liquid for surface treatment is permeated, the recording medium described in JP O.P.I. No. 55-5830 which is constituted by a support and an ink absorbable layer coated on the support, the recording medium described in JP O.P.I. Publication No. 56-157 which contains non-colloidal silica as a pigment, the recording medium described in JP O.P.I. No. 57-107878 in which an inorganic pigment and an organic pigment are used in combination, the recording medium described in JP O.P.I. No. 58-110287 which has two peaks in the distribution of pores, the recording medium described in JP O.P.I. No. 62-111782 which has upper and lower porous layers, recording medium described in JP O.P.I. Nos. 59-68292, 59-123696 and 60-18383 which has irregular-shaped cracks, the recording medium described in JP O.P.I. Nos. 61-135786, 61-148092 and 62-149475 which has a fine powder layer, the recording medium described in JP O.P.I. Nos. 62-252779, 1-108083, 2-136279, 3-65376 and 3-27976 which contains a pigment or a fine particle of silica each having a specified physical property, the recording medium described in JP O.P.I. Nos. 57-14091, 60-219083, 60-210984, 61-20797, 61-188183, 5-278324, 6-92011, 6-183134, 7-137431 and 7-276789 which contains a fine particle of silica such as colloidal silica, and the recording medium described in JP O.P.I. Nos. 2-276671, 3-67684, 3-215082, 3-251488, 4-67986, 4-263083 and 5-16517 which contains a fine particle of hydrated alumina. However, one satisfying the requirements is not found yet.
JP O.P.I. No. 2001-209310 discloses a producing method of inorganic pigment suspension for raising the production efficiency. JP O.P.I. Nos. 2000-27093 and 2002-2094 describe techniques for inhibiting the coating fault and raising the production efficient, but technique satisfying the requirement is not found yet.